This invention relates to a collar bearing for a telescopic boom for the sliding support of two telescopic sections in the collar region of the outer telescopic section.
Telescopic booms consist of an articulation section and several sections shiftably mounted in this articulation section. The drive for telescoping the boom is effected via a telescoping cylinder which is mounted at the end in the region of the bottom of the articulation section.
Depending on the dimensioning of the crane it can occur that the telescopic boom is too heavy for being transported with the crane. In this case, the telescopic boom is demounted for the transport and traveled to the site of use separate from the crane. In the case of very long and heavy telescopic booms it can be required to split the boom into individual telescopic sections or individual groups of telescopic sections for transport purposes and only mount the same at the site of use.
Individual telescopic sections of a telescopic boom usually are mounted one inside the other for a relative movement over various bearing points. At the inner telescopic section first bearing points therefore are provided on the outer circumference of the lower end. These bearing points are firmly fixed at the inner telescopic section and during the telescoping movement move along with the inner telescopic section. A second bearing point is provided at the outer telescopic section in the region of its collar. This bearing point, also referred to as collar bearing, is stationarily attached to the inner circumference of the collar.
For the assembly of a telescopic boom the collar bearing of the outer telescopic section must be removed, in order to insert the inner telescopic section into the cavity of the outer section. Up to now, no possibility is known for automatically mounting the collar bearing during the assembly operation.